package backup

import (
	"log"

	"github.com/joho/godotenv"
	"github.com/spf13/viper"
)

// Configuration holds the complete application configuration
type Configuration struct {
	Defaults DefaultsConfig          `mapstructure:"defaults"`
	Services map[string]ServiceGroup `mapstructure:"services"`
}

// DefaultsConfig holds the default settings for all services
type DefaultsConfig struct {
	Retention RetentionConfig `mapstructure:"retention"`
}

// ServiceGroup represents a service group with a common directory and multiple backup configurations
type ServiceGroup struct {
	Directory     string                  `mapstructure:"directory,omitempty"`
	Source        SourceConfig            `mapstructure:"source"`
	Hooks         HooksConfig             `mapstructure:"hooks"`
	BackupConfigs map[string]BackupConfig `mapstructure:"backup_configs"`
}

// SourceConfig represents source configuration for backups
type SourceConfig struct {
	Host   string `mapstructure:"host"`
	Path   string `mapstructure:"path"`
	SSHKey string `mapstructure:"ssh_key"`
}

// HooksConfig contains the hooks to run before and after the backup
type HooksConfig struct {
	BeforeHook string `mapstructure:"before_hook"`
	AfterHook  string `mapstructure:"after_hook"`
}

// BackupConfig represents a specific backup configuration
type BackupConfig struct {
	BackupStrategy StrategyConfig `mapstructure:"backup_strategy"`
}

// StrategyConfig represents a backup strategy configuration
type StrategyConfig struct {
	Type        string          `mapstructure:"type"`
	Provider    string          `mapstructure:"provider"`
	Options     string          `mapstructure:"options,omitempty"`
	Retention   RetentionConfig `mapstructure:"retention,omitempty"`
	Destination DestConfig      `mapstructure:"destination"`
}

// RetentionConfig represents retention policy configuration
type RetentionConfig struct {
	KeepLatest  int `mapstructure:"keep_latest"`
	KeepHourly  int `mapstructure:"keep_hourly"`
	KeepDaily   int `mapstructure:"keep_daily"`
	KeepWeekly  int `mapstructure:"keep_weekly"`
	KeepMonthly int `mapstructure:"keep_monthly"`
	KeepYearly  int `mapstructure:"keep_yearly"`
}

// DestConfig represents destination configuration for remote backups
type DestConfig struct {
	Host   string `mapstructure:"host,omitempty"`
	Path   string `mapstructure:"path"`
	SSHKey string `mapstructure:"ssh_key,omitempty"`
}

// LoadConfig loads the application configuration from a file
func LoadConfig(configPath string) (*Configuration, error) {
	if err := godotenv.Load(); err != nil {
		log.Printf("Warning: Error loading .env file: %v", err)
	}

	viper.SetConfigFile(configPath)
	if err := viper.ReadInConfig(); err != nil {
		return nil, err
	}

	var config Configuration
	if err := viper.Unmarshal(&config); err != nil {
		return nil, err
	}

	// Apply default retention settings where needed
	for serviceName, service := range config.Services {
		for configID, backupConfig := range service.BackupConfigs {
			// If retention is not set, use defaults
			if isRetentionEmpty(backupConfig.BackupStrategy.Retention) {
				backupConfig.BackupStrategy.Retention = config.Defaults.Retention
				service.BackupConfigs[configID] = backupConfig
			}
		}
		config.Services[serviceName] = service
	}

	return &config, nil
}

// isRetentionEmpty checks if a retention config is empty (all zeros)
func isRetentionEmpty(retention RetentionConfig) bool {
	return retention.KeepLatest == 0 &&
		retention.KeepHourly == 0 &&
		retention.KeepDaily == 0 &&
		retention.KeepWeekly == 0 &&
		retention.KeepMonthly == 0 &&
		retention.KeepYearly == 0
}